Eisenberger R Learned industriousness. Psychol Rev. 1992 Apr;99(2):248-67. Review.
Faul F, Erdfelder E, Lang AG, Buchner A G*Power 3: a flexible statistical power analysis program for the social, behavioral, and biomedical sciences. Behav Res Methods. 2007 May;39(2):175-91.
Godin G, Shephard RJ A simple method to assess exercise behavior in the community. Can J Appl Sport Sci. 1985 Sep;10(3):141-6.
Hill PL, Roberts BW The role of adherence in the relationship between conscientiousness and perceived health. Health Psychol. 2011 Nov;30(6):797-804. doi: 10.1037/a0023860. Epub 2011 May 23.
McAuley E & Rudolph D Physical activity, aging, and psychological well-being. Journal of Aging and Physical Activity 3: 67-96, 1995.
National Heart, Lung, and Blood Institute (2012, July 13). How are overweight and obesity diagnosed? Retrieved from http://www.nhlbi.nih.gov/health/health-topics/topics/obe/diagnosis.html
U S. Department of Health and Human Services. 2008 physical activity guidelines for Americans. Washington DC: U.S. Department of Health and Human Services, 2008.
Webb TL & Sheeran P Identifying good opportunities to act: Implementation intentions and cue discrimination. European Journal of Social Psychology, 34: 407-419, 2004.
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.
